I'm trying to run a function, but gets Undefined reference 'createList'.

#include <stdio.h>>
#include <stdlib.h>

void createList();

struct node{

    int classList;
    struct node *next;
}*Node;

int main()
{
    struct node *head = NULL;
    int choice, n, info;
    int classList;

    printf("* ****Select an option from menu**** \n");
    printf("1. Create List\n");
    printf("2. Display List\n");
    printf("3. Insert List\n");
    printf("4. Remove List\n");
    printf("5. Search List\n");
    printf("6. Exit");
    scanf("%d", &choice);

    switch(choice)
    {
      case 1: createList();
         break;
      /*case 2: displayList();
         break;
      case 3: insertList();
         break;
      case 4: removeList();
         break;
      case 5: searchList(n);
         break;
      case 6: printf("Exit");
         break;*/

}

void createList()
{
    struct node *ptr, *tmp;
    if(Node == NULL)
    {
        Node = (struct node *)malloc(sizeof(struct node));
        Node ->classList = info;
        Node ->next=NULL;
    }
    else
    {
        printf("Enter data for list 1: \n");
        scanf("%d", &classList);

        ptr = Node;
        while(ptr != NULL)
        {
            ptr = ptr ->next;
        }
        tmp = (struct node *)malloc(sizeof(struct node));
        tmp->classList=info;
        tmp->next=NULL;
        ptr->next=tmp;
    }
}

}